Brake lining grinder



Dec. 1942. I 9, BL Z K ETAL 2,304,674

BRAKE LINING GRINDER Filed July 19, 1940 Fig. 1

INVENTOR'S.

JOHN Y El. AZEK GILBERT E. SEARS VERNON R? ROY ATTORNEYS. I

Patented Dec. 8, 1942 BRAKE LINING GRINDER John Y. Blazek, Bedford, and Gilbert E. Sears and. Vernon R. Roy, Cleveland, Ohio, assignors to Lempco Products, Inc.

Application July 19, 1940, Serial No. 346,366

Claims.

This invention relates generally to brake shoe grinders but has reference more particularly to a device of the character described, the use of which does not necessitate dismantling of the brake shoe.

Broadly speaking, devices of this type are old and comprise means for chucking a bearing surface upon an axle shaft and grinding means journaled on such bearing surface for grinding the brake lining. The grinding means of devices heretofore known frequently injuriously contacted elements other than the brake lining. One of the objects of this invention has been to provide means for restricting the movement of the grinding means and therefore prevent the injurious effect just mentioned.

Another object of this invention has been to provide means for chucking the bearing surface upon the axle shaft regardless of the extent to which the axle shaft projects beyond the brake shoes.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims; the annexed drawing and the following description setting forth in detail certain structure embodying the invention, such disclosed means constituting, however, but one of the various structural forms in which the principle of the invention may be used.

In said annexed drawing:

Fig. 1 is a partially fragmentary side elevation of a device having incorporated therein the principal features of this invention;

Fig. 2 is a vertical cross-section of certain of the elements seenin 1; and

Fig. 3 is a side elevation of a device embodying this invention mounted upon an axle shaft and in grinding relation with brake lining.

The chucking means heretofore referred to will be described first, reference being had particularly to Figs. 1 and 2. Such chucking means preferably comprise a one-piece or unitary sleeve 5 which is adapted to freely fit over an axle shaft indicated by A. This sleeve is provided with two sets of radiall extending openings 6 and 1 respectively, preferably three to a set. Disposed for reciprocation in these openings is a pair of sets of pins 9 and it, the pins 6 being for the opening 6 and the pins It being for the opening l. These pins are normally urged outwardly by a spring I! which is retained interiorly of the sleeve by a screw i2 and which at each end thereof is provided with an axially extending slot 14 into which freely projects an inner nipple E6 of a pin. These nipples engage the axle shaft and the pins are manually removable upwardly.

Individual cam means are provided for each set of pins for simultaneously actuating the pins of each set. The sleeve 5 is provided with exterior threads 16 which mesh with interior threads of a cam ring 26. As is seen in Fig. l, the left face 2! of the ring 28 is conical and engages a complementary face 22 of the pins 9. Thus it will be readily seen that rotation of the ring 26 in one direction will force the pins 9 simultaneously inwardly and thatrotation of this ring in the opposite direction will free the pins ii so that the springs H may force the latter outwardly against the conical surface.

I have found that after a relatively short period of use the threads l8 and the meshing threads of the ring 2d become slightly worn or sloppy so that the conical surface 2! or the entire ring 20 does not maintain its original desirable co-axial relationship with the sleeve 5.

When such co-axial relationship ceases to exist it will be readily seen by those who are skilled in the art to which this invention pertains that the chuck itself is not co-axial with the axle shaft A. Consequently the bearing surface heretofore referred to likewise is not co-axial with the axle shaft. It follows that the same error will appear in the brake lining.

, In order to maintain and insure co-axial relationship between the ring 2k] and the sleeve 5, the outer cylindrical surface 25 of the latter is ground and the inner cylindrical surface 26 of the ring 2t is also ground and are journaled one upon the other. Thus, any tendency of the ring to tilt with respect to the sleeve will be resisted and counteracted not only by the threads but also by the journaled surfaces 25 and 26. The outer cylindrical surface 28 of the ring 28 is ground and thus provides the said bearing surface. In order to facilitate rotation of the ring 26 the same may be knurled or otherwise ruffed as at 29.

It is to be noted that in Fig. 1 the two sets of pins are closer together than they are in Fig. 2. Thus the chuck is adapted for use on axle shafts which do not project outwardly as far as the openings i. For this reason a third set of circumferentially spaced openings 32 are provided between the openings 6 and I and the openings 32 are staggered with respect to the openings 6 and 1. In between the openings i there is a Spring 33, retained by a screw 34, the former projecting over the opening 32 and provided with a slot 35 which is similar to the slot M. The openings 32 are of the same diameter as the openings 1 so that the pins i9 may be manually removed from the openings 1 and simply dropped into the openings 32 whereupon they will engage the slot 35 of the spring 33. When the pins H] are in the openings 33 they will appear as in Fig. 1.

For actuating the pins 9 inwardly, cam means are provided which are similar to the cam means described with respect to the pins 9. The righthand end of the sleeve is provided with threads 39 which extend axially for a distance much greater than do the threads l8, such distance being at least equal to the distance between the openings 1 and 32. The outer surface 39 of the sleeve between the two threads is ground as is the surface 25. A ring 4| is provided which is similar to the ring 29 except that its axial length is greater so that when it is cooperating with the openings 32, it has a greater area journaled to the surface 39 than the sleeve has to the surface 25. In respects not described the two rings may be taken to be identical. Thus it will be seen that the ring 4| when actuated to the right of Fig. 1 will eventually free the pins H] which may then be manually removed from the openings 32 and inserted into the openings 1 whereupon manipulation of the ring 4| to the left of Fig. 1 simultaneously actuates the pins i0 inwardly in the openings 1. From the foregoing it will be seen that when the pins 9 and I0 are in impinging engagement with the axle shaft, then the bearing surface 28 of the ring 29 and the similar bearing surface of the ring 4| will at all times be co-axial with the axle shaft.

Journaled for rotation about the bearing surface 28 and the bearing surface of the ring 4| is a barrel from which projects an arm 46. grinding disc 49 adapted for engaging the brake shoe 5D, is by means of a screw 48 adjustably supported by this arm so that upon rotation of the barrel about the axle shaft, both of the brake shoes will be ground to a true cylindrical surface co-axial with the axle shaft.

The above described injurious effect occurs when the barrel moves with respect to the sleeve 5 axially to the left of Fig. 3. In order to insure against this, an arm is secured, as by bolting 56, to the barrel and is provided with a suitable screw 53, the inner end of which is adapted for engaging the right end of the sleeve 5. As the barrel rotates about the sleeve, the screw 58 engages the end surface 60 and prevents the barrel from moving axially toward the brake shoes. By adjusting the screw 58 the barrel may be set at various axial positions relatively to the sleeve.

It will of course be understood that the grind wheel 49 is purely illustrative and that any instrument may be substituted therefor for acting upon the brake lining.

Other modes of applying the principle of our invention may be employed instead of the one explained, change being made as regards the structure herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

We therefore particularly point and distinctly claim as our invention:

1. In a device of the character described, a barrel, an instrument supported by the barrel, and means for rotatably mounting the barrel on a. shaft, said means comprising a sleeve adapted to loosely fit about the shaft, a set of pins disposed for reciprocation in the sleeve, and a ring threaded to said sleeve and having thereon a cam surface for actuating said pins, said ring and said sleeve each having continuous cylindrical surfaces journaled upon each other.

2. The combination of a barrel, an instrument supported thereby and means for rotatably mounting said barrel upon a shaft, said means comprising a sleeve adapted for freely fitting over said shaft, said sleeve having an outer cylindrical surface, a plurality of pins disposed for radial reciprocation in said sleeve, and cam means journaled on said cylindrical surface and in threaded engagement with said sleeve for simultaneously actuating said pin, said cam means 0 having an outer cylindrical surface adapted for rotatably receiving said barrel.

3. The combination of a barrel, an instrument supported thereby and means for. rotatably mounting said barrel upon a shaft, said means comprising a sleeve adapted for freely fitting over said shaft and provided with radial openings, said sleeve having a cylindrical surface and a threaded surface, a plurality of pins adapted for reciprocation by said openings, and cam means journalled on said cylindrical surface and in threaded engagement with said threaded surface for simultaneously actuating said pins.

4. In a device of the character described, a barrel, an instrument supported by said barrel, and means for rotatably mounting said barrel upon a shaft, said means comprising a sleeve having a pair of sets of openings, said sleeve having threads extending a distance at least equal to the distance between said sets of openings, a set of pins one for each of the openings of one of said sets, said pins being receivable by either of said sets of openings, and a ring threaded to said sleeve threads and having a cam surface adapted for actuating said pins whereby actuation of said ring relatively to said sleeve by means of the threads positions said surface for actuation of said pins regardless of with which of said sets of openings said pins are associated.

5. The combination of a barrel, an instrument supported thereby, and means for rotatably mounting said barrel upon a shaft, said means comprising a sleeve presenting a continuous and smooth surface and a threaded area, a plurality of pins disposed for reciprocation in said sleeve, and a single unitary cam ring a portion of which is journaled to said surface and another portion of which is threaded to said area for simultaneously actuating said pins.

JOHN Y. BLAZEK. VERNON R. ROY. GILBERT E. SEARS. 

